The hunt for co₂ - the key to the green transition
Capturing carbon dioxide and then pushing it into the bedrock for storage for thousands of years. It may sound like science fiction, but the technology plays a crucial part if we are to meet international climate goals.
The starting point is clear: The world has agreed to reduce greenhouse gas emissions to keep warming to 1.5 degrees. To reach the target, we must reduce our dependence on fossil fuels and invest more in renewable energy sources while improving energy efficiency.
”Industries, production facilities and power plants will have to switch to green resources such as biomass. This still results in greenhouse gas emissions, but it is carbon that is already part of the cycle, unlike fossil raw materials that add new carbon dioxide to the atmosphere," says Isabella Herstad Norin, Process Engineer and responsible for green transition in Industry at COWI Sweden.
Her area of expertise is CCS - Carbon Capture and Storage - capturing carbon dioxide from the processes that create emissions and prevent it from reaching the atmosphere and contribute to rising temperatures. We'll come back to the details of how the technology works and instead focus on the role it plays in the ongoing green transition. If we are moving away from fossil fuels, what is the point in capturing emissions? Well, according to the Intergovernmental Panel on Climate Change (IPCC), the transition is not happening fast enough.
The IPCC makes scenarios for how much the climate is affected based on the activities that society is doing to adapt, and which activities are realistically feasible soon. They see that we will not be able to switch to biofuels and renewable energy sources at the rate required to meet the 1.5-degree temperature increase goal.
So, while industries and power plants are moving from fossil fuels, they can use CCS to reduce their emissions. A refinery that currently uses oil as a raw material or a cement manufacturing plant can use CCS to become climate neutral during the transition. Other facilities that already use biofuels, such as a power plant, can capture their emissions and thus contribute to removing carbon dioxide from the atmosphere and from the cycle. Capturing carbon dioxide with Bio-CCS is called negative emissions.
Captured carbon dioxide can then go on to be stored in geological formations in the bedrock or used as a new raw material. Carbon capture clearly plays an important role during the transition, but is it a long-term solution for society? The answer is both yes and no. Even if we reach the 1.5-degree target, the IPCC's scenarios say that we will still have to remove carbon dioxide from the atmosphere. There is a long-term benefit in continuing to collect and store carbon dioxide to compensate for the CO₂ already emitted.
“But here and now, CCS can’t be an excuse to continue to use fossil fuels 'as usual'. I see it as part of the solution in certain industries and sectors where it is currently difficult to replace the entire fossil raw material stream with something biogenic within a reasonable future," says Isabella Herstad Norin.
COWI is part of several projects within CCS. In a series of articles, we delve deeper into the subject with the help of Isabella Herstad Norin, process engineer and head of green transition in Industry at COWI. The next instalment in this series focuses on the technology itself and how it works.